1. Technical Field
The present invention relates to a liquid crystal display panel of a transmissive or a semi-transmissive type having a light shielding layer made of a resin, an electronic apparatus equipped with the same, and a method for manufacturing the liquid crystal display panel.
2. Related Art
In recent years, application of a liquid crystal display device has been rapidly spread not only to an information communication device, but also to a general electrical equipment. In general, an array substrate and a color filter substrate are oppositely disposed, the peripheries thereof are bonded together by a seal material, and liquid crystal is enclosed between the both substrates to form the liquid crystal device. The array substrate is the one having a plurality of pixel electrodes provided on a first transparent substrate in a matrix manner. The color filter substrate is the one having a light shielding layer formed on a second transparent substrate in a matrix manner, a plurality of color filter layers provided to oppose each of the pixel electrodes, and a common electrode made of a transparent electrode such as ITO (Indium Tin Oxide) or IZO (Indium Tin Oxide), or the like formed on the color filter layer.
A metal material such as chrome or the like is often used in the light shielding layer formed on the color filter substrate among the liquid crystal display panel having the structure. The reason that a metal is used in this manner is that it is advantageous in the point that thin film property and high light shielding property can be obtained.
However, in recent years, a light shielding layer made of a resin material instead of the metal material has been appeared. The light shielding layer made of a resin material is cheaper than the metal material. Further, the reflectance ratio of the resin material is lower than the metal material, so that it is easy to provide high contrast. Further, influence to environment is also small. In this manner, using the resin material has the advantages than using the metal material.
Incidentally, when the light shielding layer made of a resin is used, a seal material for bonding the array substrate and the color filter substrate together is bonded on, for example, the light shielding layer. However, the light shielding layer made of a resin has low adhesiveness with the seal material as compared with the light shielding layer made of a metal material. Accordingly, there is a case that detachment phenomenon occurs at a boundary face with the seal material. Specifically, for example, it is considered that the light shielding layer made of a resin includes a black pigment so that adhesiveness between the pigment and the seal material is low.
As for a method for solving such a problem, a liquid crystal display panel in which a surface of the light shielding layer made of a resin formed in a display area and a non display area is covered by a protection film is disclosed in JP-A-11-64837 (hereinafter, referred to as Patent Document 1) and JP-A-2001-147439 (hereinafter, referred to as Patent Document 2).
As is disclosed in Patent Documents 1, 2, the problem described above can be solved if the light shielding layer made of a resin is covered by a protection film. However, when the surface of the light shielding layer is solidly covered by the protection film, each pixel area in a display area is to be also covered by the protection film. If the pixel area is covered by the protection film in this manner, there occurs a problem in that the transmittance ratio in the pixel area is lowered and a screen is displayed with a tinge of yellow.
Further, the case will be describe in which the structure in which the aforementioned light shielding layer made of a resin is used and the upper portion of the light shielding layer is further covered by the protection film is employed in a semi-transmissive liquid crystal display panel. A transparent film for adjusting a cell gap is formed at a reflective portion of a pixel area in the semi-transmissive liquid crystal display panel. Accordingly, the protection film is formed and the transparent film for adjusting a cell gap is formed in the reflective portion. Herewith, the transmittance ratio of the semi-transmissive liquid crystal display panel is further lowered.
Further, when the semi-transmissive liquid crystal display panel equipped with the light shielding layer made of a resin is manufactured, the process for forming the protection film and the process for forming the transparent film for adjusting a cell gap are required. In this case, there is a problem in that the number of manufacturing processes is increased as compared with the conventional semi-transmissive liquid crystal display panel equipped with the light shielding layer made of a metal.